1. Field of the Invention
This invention relates generally to the field of decision, uncertainty, and optimization analysis, and more particularly, to a system and method for optimizing decisions regarding a system of assets in the presence of uncertainty.
2. Description of the Related Art
There are a wide array of activities that are typically performed in the process of exploring, developing and operating oil and gas fields (assets), e.g., activities such as:                leasing land;        acquiring seismic data;        drilling exploratory wells;        drilling production wells;        completing the wells;        building facilities to process and store the production from wells.        
While these activities require large expenditures of capital, these expenditures are viewed as investments in the hope of gaining revenues (e.g., from the sale of oil and gas) that significantly exceed the total amount of the expenditures. Thus, these activities may be referred to herein as investment activities.
Each of the investment activities requires one to make various decisions, e.g., decisions regarding:                how much land to lease, and, which parcels of land to lease;        how to acquire the seismic data, and, how much seismic data to acquire;        how many exploratory wells to drill, and, where to drill to the exploratory wells;        how to develop fields;        how many production and injection wells to drill, where to drill the wells, and, what the well plan (i.e., the trajectory through space for the well bore) should be for each of the production wells;        how many perforations to make for each well, and, how to distribute perforation locations along the well plan for each well;        which order to drill and perforate wells;        what size to construct processing facilities and how to connect the wells to the facilities and to exporting systems;        how to process the fluids produced from the geologic formation;        in the cases with a plurality of potential productive assets, which assets and which order to develop and produce the assets.        
Furthermore, these decisions must be made in the context of a whole host of fundamental uncertainties, e.g., uncertainties in factors such as:                the future prices of oil and gas leases;        the amount of oil and/or gas reserves in a field;        the shape and physical properties of reservoirs in each field;        the amount of time it will take to drill each exploratory well and each production well;        the future availability of equipment such as drilling rigs and completion rigs;        the costs associated with operating and maintaining production and injection from the wells and facilities;        the future prices of oil and gas;        the stability of weather conditions.        
Any way one makes a decision, these fundamental uncertainties imply uncertainties in rewards such as production volume, revenue and profit. Therefore, there exists a need for systems and methods capable of assisting one in making decisions (each decision having a range of available options) regarding oil and gas field exploitation in view of fundamental uncertainties.